1 //===-- sanitizer_linux_libcdep.cpp ---------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is shared between AddressSanitizer and ThreadSanitizer 10 // run-time libraries and implements linux-specific functions from 11 // sanitizer_libc.h. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_platform.h" 15 16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 17 SANITIZER_OPENBSD || SANITIZER_SOLARIS 18 19 #include "sanitizer_allocator_internal.h" 20 #include "sanitizer_atomic.h" 21 #include "sanitizer_common.h" 22 #include "sanitizer_file.h" 23 #include "sanitizer_flags.h" 24 #include "sanitizer_freebsd.h" 25 #include "sanitizer_getauxval.h" 26 #include "sanitizer_glibc_version.h" 27 #include "sanitizer_linux.h" 28 #include "sanitizer_placement_new.h" 29 #include "sanitizer_procmaps.h" 30 31 #include <dlfcn.h> // for dlsym() 32 #include <link.h> 33 #include <pthread.h> 34 #include <signal.h> 35 #include <sys/resource.h> 36 #include <syslog.h> 37 38 #if !defined(ElfW) 39 #define ElfW(type) Elf_##type 40 #endif 41 42 #if SANITIZER_FREEBSD 43 #include <pthread_np.h> 44 #include <osreldate.h> 45 #include <sys/sysctl.h> 46 #define pthread_getattr_np pthread_attr_get_np 47 #endif 48 49 #if SANITIZER_OPENBSD 50 #include <pthread_np.h> 51 #include <sys/sysctl.h> 52 #endif 53 54 #if SANITIZER_NETBSD 55 #include <sys/sysctl.h> 56 #include <sys/tls.h> 57 #include <lwp.h> 58 #endif 59 60 #if SANITIZER_SOLARIS 61 #include <stdlib.h> 62 #include <thread.h> 63 #endif 64 65 #if SANITIZER_ANDROID 66 #include <android/api-level.h> 67 #if !defined(CPU_COUNT) && !defined(__aarch64__) 68 #include <dirent.h> 69 #include <fcntl.h> 70 struct __sanitizer::linux_dirent { 71 long d_ino; 72 off_t d_off; 73 unsigned short d_reclen; 74 char d_name[]; 75 }; 76 #endif 77 #endif 78 79 #if !SANITIZER_ANDROID 80 #include <elf.h> 81 #include <unistd.h> 82 #endif 83 84 namespace __sanitizer { 85 86 SANITIZER_WEAK_ATTRIBUTE int 87 real_sigaction(int signum, const void *act, void *oldact); 88 89 int internal_sigaction(int signum, const void *act, void *oldact) { 90 #if !SANITIZER_GO 91 if (&real_sigaction) 92 return real_sigaction(signum, act, oldact); 93 #endif 94 return sigaction(signum, (const struct sigaction *)act, 95 (struct sigaction *)oldact); 96 } 97 98 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, 99 uptr *stack_bottom) { 100 CHECK(stack_top); 101 CHECK(stack_bottom); 102 if (at_initialization) { 103 // This is the main thread. Libpthread may not be initialized yet. 104 struct rlimit rl; 105 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); 106 107 // Find the mapping that contains a stack variable. 108 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 109 if (proc_maps.Error()) { 110 *stack_top = *stack_bottom = 0; 111 return; 112 } 113 MemoryMappedSegment segment; 114 uptr prev_end = 0; 115 while (proc_maps.Next(&segment)) { 116 if ((uptr)&rl < segment.end) break; 117 prev_end = segment.end; 118 } 119 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end); 120 121 // Get stacksize from rlimit, but clip it so that it does not overlap 122 // with other mappings. 123 uptr stacksize = rl.rlim_cur; 124 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end; 125 // When running with unlimited stack size, we still want to set some limit. 126 // The unlimited stack size is caused by 'ulimit -s unlimited'. 127 // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 128 if (stacksize > kMaxThreadStackSize) 129 stacksize = kMaxThreadStackSize; 130 *stack_top = segment.end; 131 *stack_bottom = segment.end - stacksize; 132 return; 133 } 134 uptr stacksize = 0; 135 void *stackaddr = nullptr; 136 #if SANITIZER_SOLARIS 137 stack_t ss; 138 CHECK_EQ(thr_stksegment(&ss), 0); 139 stacksize = ss.ss_size; 140 stackaddr = (char *)ss.ss_sp - stacksize; 141 #elif SANITIZER_OPENBSD 142 stack_t sattr; 143 CHECK_EQ(pthread_stackseg_np(pthread_self(), &sattr), 0); 144 stackaddr = sattr.ss_sp; 145 stacksize = sattr.ss_size; 146 #else // !SANITIZER_SOLARIS 147 pthread_attr_t attr; 148 pthread_attr_init(&attr); 149 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 150 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); 151 pthread_attr_destroy(&attr); 152 #endif // SANITIZER_SOLARIS 153 154 *stack_top = (uptr)stackaddr + stacksize; 155 *stack_bottom = (uptr)stackaddr; 156 } 157 158 #if !SANITIZER_GO 159 bool SetEnv(const char *name, const char *value) { 160 void *f = dlsym(RTLD_NEXT, "setenv"); 161 if (!f) 162 return false; 163 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 164 setenv_ft setenv_f; 165 CHECK_EQ(sizeof(setenv_f), sizeof(f)); 166 internal_memcpy(&setenv_f, &f, sizeof(f)); 167 return setenv_f(name, value, 1) == 0; 168 } 169 #endif 170 171 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor, 172 int *patch) { 173 #ifdef _CS_GNU_LIBC_VERSION 174 char buf[64]; 175 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 176 if (len >= sizeof(buf)) 177 return false; 178 buf[len] = 0; 179 static const char kGLibC[] = "glibc "; 180 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0) 181 return false; 182 const char *p = buf + sizeof(kGLibC) - 1; 183 *major = internal_simple_strtoll(p, &p, 10); 184 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 185 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 186 return true; 187 #else 188 return false; 189 #endif 190 } 191 192 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && \ 193 !SANITIZER_NETBSD && !SANITIZER_OPENBSD && !SANITIZER_SOLARIS 194 static uptr g_tls_size; 195 196 #ifdef __i386__ 197 # define CHECK_GET_TLS_STATIC_INFO_VERSION (!__GLIBC_PREREQ(2, 27)) 198 #else 199 # define CHECK_GET_TLS_STATIC_INFO_VERSION 0 200 #endif 201 202 #if CHECK_GET_TLS_STATIC_INFO_VERSION 203 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 204 #else 205 # define DL_INTERNAL_FUNCTION 206 #endif 207 208 namespace { 209 struct GetTlsStaticInfoCall { 210 typedef void (*get_tls_func)(size_t*, size_t*); 211 }; 212 struct GetTlsStaticInfoRegparmCall { 213 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 214 }; 215 216 template <typename T> 217 void CallGetTls(void* ptr, size_t* size, size_t* align) { 218 typename T::get_tls_func get_tls; 219 CHECK_EQ(sizeof(get_tls), sizeof(ptr)); 220 internal_memcpy(&get_tls, &ptr, sizeof(ptr)); 221 CHECK_NE(get_tls, 0); 222 get_tls(size, align); 223 } 224 225 bool CmpLibcVersion(int major, int minor, int patch) { 226 int ma; 227 int mi; 228 int pa; 229 if (!GetLibcVersion(&ma, &mi, &pa)) 230 return false; 231 if (ma > major) 232 return true; 233 if (ma < major) 234 return false; 235 if (mi > minor) 236 return true; 237 if (mi < minor) 238 return false; 239 return pa >= patch; 240 } 241 242 } // namespace 243 244 void InitTlsSize() { 245 // all current supported platforms have 16 bytes stack alignment 246 const size_t kStackAlign = 16; 247 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 248 size_t tls_size = 0; 249 size_t tls_align = 0; 250 // On i?86, _dl_get_tls_static_info used to be internal_function, i.e. 251 // __attribute__((regparm(3), stdcall)) before glibc 2.27 and is normal 252 // function in 2.27 and later. 253 if (CHECK_GET_TLS_STATIC_INFO_VERSION && !CmpLibcVersion(2, 27, 0)) 254 CallGetTls<GetTlsStaticInfoRegparmCall>(get_tls_static_info_ptr, 255 &tls_size, &tls_align); 256 else 257 CallGetTls<GetTlsStaticInfoCall>(get_tls_static_info_ptr, 258 &tls_size, &tls_align); 259 if (tls_align < kStackAlign) 260 tls_align = kStackAlign; 261 g_tls_size = RoundUpTo(tls_size, tls_align); 262 } 263 #else 264 void InitTlsSize() { } 265 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && 266 // !SANITIZER_NETBSD && !SANITIZER_SOLARIS 267 268 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) || \ 269 defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) || \ 270 defined(__arm__)) && \ 271 SANITIZER_LINUX && !SANITIZER_ANDROID 272 // sizeof(struct pthread) from glibc. 273 static atomic_uintptr_t thread_descriptor_size; 274 275 uptr ThreadDescriptorSize() { 276 uptr val = atomic_load_relaxed(&thread_descriptor_size); 277 if (val) 278 return val; 279 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 280 int major; 281 int minor; 282 int patch; 283 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 284 /* sizeof(struct pthread) values from various glibc versions. */ 285 if (SANITIZER_X32) 286 val = 1728; // Assume only one particular version for x32. 287 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 288 else if (SANITIZER_ARM) 289 val = minor <= 22 ? 1120 : 1216; 290 else if (minor <= 3) 291 val = FIRST_32_SECOND_64(1104, 1696); 292 else if (minor == 4) 293 val = FIRST_32_SECOND_64(1120, 1728); 294 else if (minor == 5) 295 val = FIRST_32_SECOND_64(1136, 1728); 296 else if (minor <= 9) 297 val = FIRST_32_SECOND_64(1136, 1712); 298 else if (minor == 10) 299 val = FIRST_32_SECOND_64(1168, 1776); 300 else if (minor == 11 || (minor == 12 && patch == 1)) 301 val = FIRST_32_SECOND_64(1168, 2288); 302 else if (minor <= 14) 303 val = FIRST_32_SECOND_64(1168, 2304); 304 else 305 val = FIRST_32_SECOND_64(1216, 2304); 306 } 307 #elif defined(__mips__) 308 // TODO(sagarthakur): add more values as per different glibc versions. 309 val = FIRST_32_SECOND_64(1152, 1776); 310 #elif defined(__aarch64__) 311 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 312 val = 1776; 313 #elif defined(__powerpc64__) 314 val = 1776; // from glibc.ppc64le 2.20-8.fc21 315 #elif defined(__s390__) 316 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22 317 #endif 318 if (val) 319 atomic_store_relaxed(&thread_descriptor_size, val); 320 return val; 321 } 322 323 // The offset at which pointer to self is located in the thread descriptor. 324 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 325 326 uptr ThreadSelfOffset() { 327 return kThreadSelfOffset; 328 } 329 330 #if defined(__mips__) || defined(__powerpc64__) 331 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 332 // head structure. It lies before the static tls blocks. 333 static uptr TlsPreTcbSize() { 334 # if defined(__mips__) 335 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 336 # elif defined(__powerpc64__) 337 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 338 # endif 339 const uptr kTlsAlign = 16; 340 const uptr kTlsPreTcbSize = 341 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 342 return kTlsPreTcbSize; 343 } 344 #endif 345 346 uptr ThreadSelf() { 347 uptr descr_addr; 348 # if defined(__i386__) 349 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 350 # elif defined(__x86_64__) 351 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 352 # elif defined(__mips__) 353 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 354 // points to the end of the TCB + 0x7000. The pthread_descr structure is 355 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 356 // TCB and the size of pthread_descr. 357 const uptr kTlsTcbOffset = 0x7000; 358 uptr thread_pointer; 359 asm volatile(".set push;\ 360 .set mips64r2;\ 361 rdhwr %0,$29;\ 362 .set pop" : "=r" (thread_pointer)); 363 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 364 # elif defined(__aarch64__) || defined(__arm__) 365 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 366 ThreadDescriptorSize(); 367 # elif defined(__s390__) 368 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()); 369 # elif defined(__powerpc64__) 370 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13) 371 // points to the end of the TCB + 0x7000. The pthread_descr structure is 372 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 373 // TCB and the size of pthread_descr. 374 const uptr kTlsTcbOffset = 0x7000; 375 uptr thread_pointer; 376 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset)); 377 descr_addr = thread_pointer - TlsPreTcbSize(); 378 # else 379 # error "unsupported CPU arch" 380 # endif 381 return descr_addr; 382 } 383 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX 384 385 #if SANITIZER_FREEBSD 386 static void **ThreadSelfSegbase() { 387 void **segbase = 0; 388 # if defined(__i386__) 389 // sysarch(I386_GET_GSBASE, segbase); 390 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase)); 391 # elif defined(__x86_64__) 392 // sysarch(AMD64_GET_FSBASE, segbase); 393 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase)); 394 # else 395 # error "unsupported CPU arch" 396 # endif 397 return segbase; 398 } 399 400 uptr ThreadSelf() { 401 return (uptr)ThreadSelfSegbase()[2]; 402 } 403 #endif // SANITIZER_FREEBSD 404 405 #if SANITIZER_NETBSD 406 static struct tls_tcb * ThreadSelfTlsTcb() { 407 return (struct tls_tcb *)_lwp_getprivate(); 408 } 409 410 uptr ThreadSelf() { 411 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 412 } 413 414 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 415 const Elf_Phdr *hdr = info->dlpi_phdr; 416 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 417 418 for (; hdr != last_hdr; ++hdr) { 419 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 420 *(uptr*)data = hdr->p_memsz; 421 break; 422 } 423 } 424 return 0; 425 } 426 #endif // SANITIZER_NETBSD 427 428 #if !SANITIZER_GO 429 static void GetTls(uptr *addr, uptr *size) { 430 #if SANITIZER_LINUX && !SANITIZER_ANDROID 431 # if defined(__x86_64__) || defined(__i386__) || defined(__s390__) 432 *addr = ThreadSelf(); 433 *size = GetTlsSize(); 434 *addr -= *size; 435 *addr += ThreadDescriptorSize(); 436 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) \ 437 || defined(__arm__) 438 *addr = ThreadSelf(); 439 *size = GetTlsSize(); 440 # else 441 *addr = 0; 442 *size = 0; 443 # endif 444 #elif SANITIZER_FREEBSD 445 void** segbase = ThreadSelfSegbase(); 446 *addr = 0; 447 *size = 0; 448 if (segbase != 0) { 449 // tcbalign = 16 450 // tls_size = round(tls_static_space, tcbalign); 451 // dtv = segbase[1]; 452 // dtv[2] = segbase - tls_static_space; 453 void **dtv = (void**) segbase[1]; 454 *addr = (uptr) dtv[2]; 455 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]); 456 } 457 #elif SANITIZER_NETBSD 458 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 459 *addr = 0; 460 *size = 0; 461 if (tcb != 0) { 462 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 463 // ld.elf_so hardcodes the index 1. 464 dl_iterate_phdr(GetSizeFromHdr, size); 465 466 if (*size != 0) { 467 // The block has been found and tcb_dtv[1] contains the base address 468 *addr = (uptr)tcb->tcb_dtv[1]; 469 } 470 } 471 #elif SANITIZER_OPENBSD 472 *addr = 0; 473 *size = 0; 474 #elif SANITIZER_ANDROID 475 *addr = 0; 476 *size = 0; 477 #elif SANITIZER_SOLARIS 478 // FIXME 479 *addr = 0; 480 *size = 0; 481 #else 482 # error "Unknown OS" 483 #endif 484 } 485 #endif 486 487 #if !SANITIZER_GO 488 uptr GetTlsSize() { 489 #if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD || \ 490 SANITIZER_OPENBSD || SANITIZER_SOLARIS 491 uptr addr, size; 492 GetTls(&addr, &size); 493 return size; 494 #elif defined(__mips__) || defined(__powerpc64__) 495 return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16); 496 #else 497 return g_tls_size; 498 #endif 499 } 500 #endif 501 502 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 503 uptr *tls_addr, uptr *tls_size) { 504 #if SANITIZER_GO 505 // Stub implementation for Go. 506 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 507 #else 508 GetTls(tls_addr, tls_size); 509 510 uptr stack_top, stack_bottom; 511 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 512 *stk_addr = stack_bottom; 513 *stk_size = stack_top - stack_bottom; 514 515 if (!main) { 516 // If stack and tls intersect, make them non-intersecting. 517 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 518 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 519 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 520 *stk_size -= *tls_size; 521 *tls_addr = *stk_addr + *stk_size; 522 } 523 } 524 #endif 525 } 526 527 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 528 typedef ElfW(Phdr) Elf_Phdr; 529 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 530 #define Elf_Phdr XElf32_Phdr 531 #define dl_phdr_info xdl_phdr_info 532 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 533 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 534 535 struct DlIteratePhdrData { 536 InternalMmapVectorNoCtor<LoadedModule> *modules; 537 bool first; 538 }; 539 540 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 541 DlIteratePhdrData *data = (DlIteratePhdrData*)arg; 542 InternalScopedString module_name(kMaxPathLength); 543 if (data->first) { 544 data->first = false; 545 // First module is the binary itself. 546 ReadBinaryNameCached(module_name.data(), module_name.size()); 547 } else if (info->dlpi_name) { 548 module_name.append("%s", info->dlpi_name); 549 } 550 if (module_name[0] == '\0') 551 return 0; 552 LoadedModule cur_module; 553 cur_module.set(module_name.data(), info->dlpi_addr); 554 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 555 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 556 if (phdr->p_type == PT_LOAD) { 557 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 558 uptr cur_end = cur_beg + phdr->p_memsz; 559 bool executable = phdr->p_flags & PF_X; 560 bool writable = phdr->p_flags & PF_W; 561 cur_module.addAddressRange(cur_beg, cur_end, executable, 562 writable); 563 } 564 } 565 data->modules->push_back(cur_module); 566 return 0; 567 } 568 569 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 570 extern "C" __attribute__((weak)) int dl_iterate_phdr( 571 int (*)(struct dl_phdr_info *, size_t, void *), void *); 572 #endif 573 574 static bool requiresProcmaps() { 575 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 576 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 577 // The runtime check allows the same library to work with 578 // both K and L (and future) Android releases. 579 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 580 #else 581 return false; 582 #endif 583 } 584 585 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 586 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 587 memory_mapping.DumpListOfModules(modules); 588 } 589 590 void ListOfModules::init() { 591 clearOrInit(); 592 if (requiresProcmaps()) { 593 procmapsInit(&modules_); 594 } else { 595 DlIteratePhdrData data = {&modules_, true}; 596 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 597 } 598 } 599 600 // When a custom loader is used, dl_iterate_phdr may not contain the full 601 // list of modules. Allow callers to fall back to using procmaps. 602 void ListOfModules::fallbackInit() { 603 if (!requiresProcmaps()) { 604 clearOrInit(); 605 procmapsInit(&modules_); 606 } else { 607 clear(); 608 } 609 } 610 611 // getrusage does not give us the current RSS, only the max RSS. 612 // Still, this is better than nothing if /proc/self/statm is not available 613 // for some reason, e.g. due to a sandbox. 614 static uptr GetRSSFromGetrusage() { 615 struct rusage usage; 616 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 617 return 0; 618 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 619 } 620 621 uptr GetRSS() { 622 if (!common_flags()->can_use_proc_maps_statm) 623 return GetRSSFromGetrusage(); 624 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 625 if (fd == kInvalidFd) 626 return GetRSSFromGetrusage(); 627 char buf[64]; 628 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 629 internal_close(fd); 630 if ((sptr)len <= 0) 631 return 0; 632 buf[len] = 0; 633 // The format of the file is: 634 // 1084 89 69 11 0 79 0 635 // We need the second number which is RSS in pages. 636 char *pos = buf; 637 // Skip the first number. 638 while (*pos >= '0' && *pos <= '9') 639 pos++; 640 // Skip whitespaces. 641 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 642 pos++; 643 // Read the number. 644 uptr rss = 0; 645 while (*pos >= '0' && *pos <= '9') 646 rss = rss * 10 + *pos++ - '0'; 647 return rss * GetPageSizeCached(); 648 } 649 650 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 651 // they allocate memory. 652 u32 GetNumberOfCPUs() { 653 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD 654 u32 ncpu; 655 int req[2]; 656 uptr len = sizeof(ncpu); 657 req[0] = CTL_HW; 658 req[1] = HW_NCPU; 659 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 660 return ncpu; 661 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 662 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 663 // exist in sched.h. That is the case for toolchains generated with older 664 // NDKs. 665 // This code doesn't work on AArch64 because internal_getdents makes use of 666 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 667 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 668 if (internal_iserror(fd)) 669 return 0; 670 InternalMmapVector<u8> buffer(4096); 671 uptr bytes_read = buffer.size(); 672 uptr n_cpus = 0; 673 u8 *d_type; 674 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 675 while (true) { 676 if ((u8 *)entry >= &buffer[bytes_read]) { 677 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 678 buffer.size()); 679 if (internal_iserror(bytes_read) || !bytes_read) 680 break; 681 entry = (struct linux_dirent *)buffer.data(); 682 } 683 d_type = (u8 *)entry + entry->d_reclen - 1; 684 if (d_type >= &buffer[bytes_read] || 685 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 686 break; 687 if (entry->d_ino != 0 && *d_type == DT_DIR) { 688 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 689 entry->d_name[2] == 'u' && 690 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 691 n_cpus++; 692 } 693 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 694 } 695 internal_close(fd); 696 return n_cpus; 697 #elif SANITIZER_SOLARIS 698 return sysconf(_SC_NPROCESSORS_ONLN); 699 #else 700 cpu_set_t CPUs; 701 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 702 return CPU_COUNT(&CPUs); 703 #endif 704 } 705 706 #if SANITIZER_LINUX 707 708 # if SANITIZER_ANDROID 709 static atomic_uint8_t android_log_initialized; 710 711 void AndroidLogInit() { 712 openlog(GetProcessName(), 0, LOG_USER); 713 atomic_store(&android_log_initialized, 1, memory_order_release); 714 } 715 716 static bool ShouldLogAfterPrintf() { 717 return atomic_load(&android_log_initialized, memory_order_acquire); 718 } 719 720 extern "C" SANITIZER_WEAK_ATTRIBUTE 721 int async_safe_write_log(int pri, const char* tag, const char* msg); 722 extern "C" SANITIZER_WEAK_ATTRIBUTE 723 int __android_log_write(int prio, const char* tag, const char* msg); 724 725 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 726 #define SANITIZER_ANDROID_LOG_INFO 4 727 728 // async_safe_write_log is a new public version of __libc_write_log that is 729 // used behind syslog. It is preferable to syslog as it will not do any dynamic 730 // memory allocation or formatting. 731 // If the function is not available, syslog is preferred for L+ (it was broken 732 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 733 // interceptor. Fallback to __android_log_write pre-L. 734 void WriteOneLineToSyslog(const char *s) { 735 if (&async_safe_write_log) { 736 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 737 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 738 syslog(LOG_INFO, "%s", s); 739 } else { 740 CHECK(&__android_log_write); 741 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 742 } 743 } 744 745 extern "C" SANITIZER_WEAK_ATTRIBUTE 746 void android_set_abort_message(const char *); 747 748 void SetAbortMessage(const char *str) { 749 if (&android_set_abort_message) 750 android_set_abort_message(str); 751 } 752 # else 753 void AndroidLogInit() {} 754 755 static bool ShouldLogAfterPrintf() { return true; } 756 757 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 758 759 void SetAbortMessage(const char *str) {} 760 # endif // SANITIZER_ANDROID 761 762 void LogMessageOnPrintf(const char *str) { 763 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 764 WriteToSyslog(str); 765 } 766 767 #endif // SANITIZER_LINUX 768 769 #if SANITIZER_LINUX && !SANITIZER_GO 770 // glibc crashes when using clock_gettime from a preinit_array function as the 771 // vDSO function pointers haven't been initialized yet. __progname is 772 // initialized after the vDSO function pointers, so if it exists, is not null 773 // and is not empty, we can use clock_gettime. 774 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 775 INLINE bool CanUseVDSO() { 776 // Bionic is safe, it checks for the vDSO function pointers to be initialized. 777 if (SANITIZER_ANDROID) 778 return true; 779 if (&__progname && __progname && *__progname) 780 return true; 781 return false; 782 } 783 784 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 785 // clock_gettime. real_clock_gettime only exists if clock_gettime is 786 // intercepted, so define it weakly and use it if available. 787 extern "C" SANITIZER_WEAK_ATTRIBUTE 788 int real_clock_gettime(u32 clk_id, void *tp); 789 u64 MonotonicNanoTime() { 790 timespec ts; 791 if (CanUseVDSO()) { 792 if (&real_clock_gettime) 793 real_clock_gettime(CLOCK_MONOTONIC, &ts); 794 else 795 clock_gettime(CLOCK_MONOTONIC, &ts); 796 } else { 797 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 798 } 799 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 800 } 801 #else 802 // Non-Linux & Go always use the syscall. 803 u64 MonotonicNanoTime() { 804 timespec ts; 805 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 806 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 807 } 808 #endif // SANITIZER_LINUX && !SANITIZER_GO 809 810 #if !SANITIZER_OPENBSD 811 void ReExec() { 812 const char *pathname = "/proc/self/exe"; 813 814 #if SANITIZER_NETBSD 815 static const int name[] = { 816 CTL_KERN, 817 KERN_PROC_ARGS, 818 -1, 819 KERN_PROC_PATHNAME, 820 }; 821 char path[400]; 822 uptr len; 823 824 len = sizeof(path); 825 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) 826 pathname = path; 827 #elif SANITIZER_SOLARIS 828 pathname = getexecname(); 829 CHECK_NE(pathname, NULL); 830 #elif SANITIZER_USE_GETAUXVAL 831 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that 832 // rely on that will fail to load shared libraries. Query AT_EXECFN instead. 833 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN)); 834 #endif 835 836 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); 837 int rverrno; 838 CHECK_EQ(internal_iserror(rv, &rverrno), true); 839 Printf("execve failed, errno %d\n", rverrno); 840 Die(); 841 } 842 #endif // !SANITIZER_OPENBSD 843 844 } // namespace __sanitizer 845 846 #endif 847